Building blocks with improved insulating properties are well known to those skilled in the art. Thus, for example, a number of such building blocks are described in column 1 of U.S. Pat. No. 4,185,434 of Jones. As is disclosed in the Jones patent, most of the prior art building blocks contain webs or bridges across the ends and/or the middle of them between the cavities, and an unacceptable amount of heat is lost through these thermally conductive paths.
The Jones patent discloses a building block which does not contain connecting webs or bridges between its front and rear walls, which are maintained in spaced relationship by an insulating material between them; and it claims a wall construction comprised of a plurality of such building blocks. However, such wall construction may contain connecting mortar bridges or openings between the building blocks, and heat may readily flow from one side of a wall to the other.
The interior walls of the building block of the Jones patent define a multiplicity of right angles, and the interior surfaces of this building block create many stress points, thereby facilitating fracture upon the application of stress.
Another insulated building block is disclosed by U.S. Pat. No. 4,551,959 of Schmid. This building block has two spaced supportive parts separated from one another by a quantity of insulating material positioned between the parts. At column 2 of his patent, Schmid discloses a building block in which the insulating portion extends slightly beyond the confines of the space between its block parts so that, when the block is used in a wall in which adjacent blocks of like construction are joined with mortar, its insulating portion engages the insulating portion of an adjacent block and provides, with the insulating portion of adjacent blocks, a continuous barrier of insulation through the wall.
The two parts of the building block of the Schmid patent are held together by insulating material between such parts. When the block of the Schmid patent is subjected to conditions which will tend to degrade and/or weaken the insulating material (such as those one might encounter in a fire), the Schmid block will tend to lose its structural integrity.
It is an object of this invention to provide a building block which does not contain thermally conductive webs or bridges between the walls which allow the flow of heat from one wall to another.
It is another object of this invention to provide a building block which, when it is joined to one or more adjacent building blocks of similar construction with mortar, will form a wall construction which does not contain webs or bridges between its walls allowing the flow of heat from one side of the wall to the other.
It is yet another object of this invention to provide a building block which does not contain any large air cavities.
It is yet another object of this invention to provide a building block which will retain its structural integrity when the insulating material in it is weakened or destroyed.
It is yet another object of this invention to provide a building block which, when joined with mortar to building blocks of similar construction, will provide a construction wall which is less likely to crack when subjected to stress from earthquakes than prior art construction walls.
It is yet another object of this invention to provide a building block with improved sound insulating properties.
It is yet another object of this invention to provide a building block with improved heat storage properties.